Restart or Soft Reset iPhone:
If your iPhone is not working right , try restarting iPhone, forcing an app to quit, or resetting iPhone.

Soft Restart iPhone:
Hold down the Sleep/Wake button until the red slider appears. Slide your finger across the slider to turn off iPhone.

To turn iPhone back on, hold down the Sleep/Wake button until the Apple logo appears.

Force an app to quit:
From the Home screen, double-click the Home button and swipe upwards on the app screen.
If you can’t turn off iPhone or if the problem continues, you may need to reset iPhone. Do this only if you’re unable to restart your iPhone.